On a revisited Moore-Penrose inverse of a linear operator on Hilbert spaces

[EN] For two given Hilbert spaces H and K and a given bounded linear operator A is an element of L(H, K) having closed range, it is well known that the Moore-Penrose inverse of A is a reflexive g-inverse G is an element of L ( K; H) of A which is both minimum norm and least squares. In this paper, weaker equivalent conditions for an operator G to be the Moore-Penrose inverse of A are investigated in terms of normal, EP, bi-normal, bi-EP, l-quasi-normal and r-quasi-normal and l-quasi-EP and r-quasi-EP operators.Research partially supported by Ministerio de Economia y Competitividad of Spain (grant DGI MTM2013-43678-P and Red de Excelencia MTM2015-68805-REDT)Malik, SB.; Thome, N. (2017). On a revisited Moore-Penrose inverse of a linear operator on Hilbert spaces. Filomat. 31(7):1927-1931. https://doi.org/10.2298/FIL1707927MS1927193131

The mm-weak core inverse

Since the day the core inverse has been known in a paper of Bakasarly and Trenkler, it has been widely researched. So far, there are four generalizations of this inverse for the case of matrices of an arbitrary index, namely, the BT inverse, the DMP inverse, the core-EP inverse and the WC inverse. In this paper we introduce a new type of generalized inverse for a matrix of arbitrary index to be called $m$-weak core inverse which generalizes the core-EP inverse, the WC inverse, and therefore the core inverse. We study several properties and characterizations of the $m$-weak core inverse by using matrix decompositions

Neuroprotective and hepatoprotective effect of whole red rice forms against oxidative stress in streptozotocin induced diabetic rats.

151-160Whole red rice (Oryza sativa L.), consumed as staple food in many countries worldwide, is rich in phytochemicals, mainly antioxidants having health potency. The present study evaluated the neuro- and hepatoprotective efficacy of raw and parboiled whole red rice against streptozotocin (STZ) induced oxidative stress, and antioxidant metabolism both in diabetic and normal non-diabetic rats. Wistar rats were rendered diabetic by a single intraperitoneal (i.p.) injection of streptozotocin (45 mg/kg body wt.), supplemented with raw and parboiled whole red rice for six weeks. Results revealed a drastic increase in oxidative stress markers, such as lipid peroxidation, nitric oxide (NO) level, hydroperoxide (HP) level; antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), thioredoxin reductases (TR), glutathione S-transferase (GST), acetylcholinesterase (AChE) activity, and decrease in endogenous antioxidant, glutathione (GSH) in diabetic rat. On the other hand, addition of raw and parboiled whole red rice in the diet counteracted the STZ induced oxidative stress in diabetic groups and improved the neuro and hepatic antioxidant system. Both, parboiled and raw red rice forms, exercised similar impacts in diabetic as well as in normal rats suggesting improved antioxidant defence mechanism. Results have shown that the whole red rice possess antidiabetic potential with the antioxidant improving ability, and could be utilized as dietary supplements in diabetes management

The class of m-EP and m-normal matrices

The well-known classes of EP matrices and normal matrices are de- fined by the matrices that commute with their Moore-Penrose inverse and with their conjugate transpose, respectively. This paper investigates the class of m-EP matrices and m-normal matrices that provide a generalization of EP matrices and normal matrices, respectively, and analyzes both of them for their properties and characterizations.Third author was partially supported by Ministerio de Economia y Competitividad of Spain [grant number DGI MTM2013-43678-P], [Red de Excelencia MTM2015-68805-REDT].Malik, SB.; Rueda, L.; Thome, N. (2016). The class of m-EP and m-normal matrices. Linear and Multilinear Algebra. 64(11):2119-2132. https://doi.org/10.1080/03081087.2016.1139037S21192132641

A study of superficial surgical site infections in a tertiary care hospital at Bangalore

Background: All postoperative surgical infections occurring in an operative site are termed surgical site infections (SSI). Superficial incisional surgical site infection occurs within 30 days after the operation and infection involves only skin or subcutaneous tissue of the incision and represents a substantial burden of disease for patients and health services. The study was conducted to know the incidence of surgical site infection in our hospital, risk factors associated with it and the antibiotic susceptibility pattern of the pathogens.Methods:This prospective study was carried out in the Department of Microbiology at Dr B R AMC for a period of 1 year from Jan 2013to Jan 2014. Samples of SSI received in the Microbiology laboratory were processed and Data collected.Results:The overall surgical site infection rate in our hospital during the study period is 4.3%. Staphylococcus aureus (S. aureus) was the most common isolate obtained followed by Escherichia coli (E. coli) and Coagulase negative Staphylococcus (CONS). Other organisms isolated were Pseudomonas aeruginosa, Enterococcus, Klebsiella pneumoniae and Proteus mirabilis. Among them, 88.8% of S. aureus and 50% of CONS isolates were methicillin-resistant strains. 80% of E. coli and 100% of Klebsiella species were ESBL producers. 50% of Enterococci were Vancomycin resistant. Risk factors like diabetes mellitus and duration plays a significant role in causing surgical site infection.Conclusion:Implementation of an effective infection control programme and judicious use of antibiotic prophylaxis reduces the incidence of SSI in the hospital.

A study of biofilm production in clinical isolates of Staphylococci at a tertiary care hospital, Bangalore

Background: The Biofilms are densely packed communities of microorganisms consisting of layers of cell clusters embedded in a matrix of extracellular polysaccharide called polysaccharide intercellular adhesin. This layer impedes the delivery of antibiotics to the biofilm forming microbial cells leading to emergence of drug resistance. Staphylococci are commensal bacteria on the human skin and mucous membranes. So it may be easily introduced as a contaminant during the surgical intervention. So, this study was conducted to identify the Biofilm producing strains from clinical isolates of Staphylococci.Methods: A total of 182 non-repetitive clinical strains of Staphylococci isolated from various clinical samples from Feb 2014 to Oct 2014 were included in the study. All the isolates were identified using standard microbiological procedures. All the samples were tested for biofilm production by modified Congo-red agar method and tube method.Results: Out of 182 samples that were included in the study, a total of 90 (49.45%) samples showed biofilm formation of which 58 (75.32%) were methicillin resistant and 32 (30.47%) were methicillin sensitive. Also these strains were resistant to other antibiotics.  Conclusion: Our study showed biofilm production by methicillin resistant strains which were also multidrug resistant. Treatment of methicillin resistant strains of Staphylococci is one of the most challenging task for the clinicians and the microbiologists. So they should be routinely screened for biofilm formation in order to prevent emergence and spread of multidrug resistant strains.

Covishield vaccine experience in a health care setting

Background: SARS-CoV-2 pandemic has affected the whole world and India is one among the most affected countries. Vaccination is the most important tool to halt this pandemic and vaccine hesitancy unfortunately derails vaccination drive. Vaccine hesitancy among people is mainly due to concerns about vaccine safety! This study was done to assess adverse effects of Covishield vaccine among health care workers in a single health care organization.Methods: All the vaccine recipients were requested to answer a questionnaire with demographic details and various side effects following both the doses of Covishield vaccination.Results: About 665 employees responded to the questionnaire and the most common adverse reaction following Covishield vaccine was injection site pain, which was reported by 63% of vaccinees after first dose of vaccine.Conclusions: Covishield vaccine is relatively safe and incidence of major adverse events are rare following vaccination

Structural and functional conservation of key domains in InsP3 and ryanodine receptors.

Inositol-1,4,5-trisphosphate receptors (InsP(3)Rs) and ryanodine receptors (RyRs) are tetrameric intracellular Ca(2+) channels. In each of these receptor families, the pore, which is formed by carboxy-terminal transmembrane domains, is regulated by signals that are detected by large cytosolic structures. InsP(3)R gating is initiated by InsP(3) binding to the InsP(3)-binding core (IBC, residues 224-604 of InsP(3)R1) and it requires the suppressor domain (SD, residues 1-223 of InsP(3)R1). Here we present structures of the amino-terminal region (NT, residues 1-604) of rat InsP(3)R1 with (3.6 Å) and without (3.0 Å) InsP(3) bound. The arrangement of the three NT domains, SD, IBC-β and IBC-α, identifies two discrete interfaces (α and β) between the IBC and SD. Similar interfaces occur between equivalent domains (A, B and C) in RyR1 (ref. 9). The orientations of the three domains when docked into a tetrameric structure of InsP(3)R and of the ABC domains docked into RyR are remarkably similar. The importance of the α-interface for activation of InsP(3)R and RyR is confirmed by mutagenesis and, for RyR, by disease-causing mutations. Binding of InsP(3) causes partial closure of the clam-like IBC, disrupting the β-interface and pulling the SD towards the IBC. This reorients an exposed SD loop ('hotspot' (HS) loop) that is essential for InsP(3)R activation. The loop is conserved in RyR and includes mutations that are associated with malignant hyperthermia and central core disease. The HS loop interacts with an adjacent NT, suggesting that activation re-arranges inter-subunit interactions. The A domain of RyR functionally replaced the SD in full-length InsP(3)R, and an InsP(3)R in which its C-terminal transmembrane region was replaced by that from RyR1 was gated by InsP(3) and blocked by ryanodine. Activation mechanisms are conserved between InsP(3)R and RyR. Allosteric modulation of two similar domain interfaces within an N-terminal subunit reorients the first domain (SD or A domain), allowing it, through interactions of the second domain of an adjacent subunit (IBC-β or B domain), to gate the pore